IO::Async::Test(3) User Contributed Perl Documentation IO::Async::Test(3)NAME
"IO::Async::Test" - utility functions for use in test scripts
SYNOPSIS
use Test::More tests => 1;
use IO::Async::Test;
use IO::Async::Loop;
my $loop = IO::Async::Loop->new;
testing_loop( $loop );
my $result;
$loop->do_something(
some => args,
on_done => sub {
$result = the_outcome;
}
);
wait_for { defined $result };
is( $result, what_we_expected, 'The event happened' );
...
my $buffer = "";
my $handle = IO::Handle-> ...
wait_for_stream { length $buffer >= 10 } $handle => $buffer;
is( substr( $buffer, 0, 10, "" ), "0123456789", 'Buffer was correct' );
DESCRIPTION
This module provides utility functions that may be useful when writing
test scripts for code which uses "IO::Async" (as well as being used in
the "IO::Async" test scripts themselves).
Test scripts are often synchronous by nature; they are a linear
sequence of actions to perform, interspersed with assertions which
check for given conditions. This goes against the very nature of
"IO::Async" which, being an asynchronisation framework, does not
provide a linear stepped way of working.
In order to write a test, the "wait_for" function provides a way of
synchronising the code, so that a given condition is known to hold,
which would typically signify that some event has occured, the outcome
of which can now be tested using the usual testing primitives.
Because the primary purpose of "IO::Async" is to provide IO operations
on filehandles, a great many tests will likely be based around
connected pipes or socket handles. The "wait_for_stream" function
provides a convenient way to wait for some content to be written
through such a connected stream.
FUNCTIONS
testing_loop( $loop )
Set the "IO::Async::Loop" object which the "wait_for" function will
loop on.
wait_for( $condfunc )
Repeatedly call the "loop_once" method on the underlying loop (given to
the "testing_loop" function), until the given condition function
callback returns true.
To guard against stalled scripts, if the loop indicates a timeout for
10 consequentive seconds, then an error is thrown.
wait_for_stream( $condfunc, $handle, $buffer )
As "wait_for", but will also watch the given IO handle for readability,
and whenever it is readable will read bytes in from it into the given
buffer. The buffer is NOT initialised when the function is entered, in
case data remains from a previous call.
$buffer can also be a CODE reference, in which case it will be invoked
being passed data read from the handle, whenever it is readable.
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.18.2 2014-05-14 IO::Async::Test(3)
